This relates to integrated circuits, and more particularly, to integrated circuit inductors.
It is often necessary to form inductors on integrated circuits. Inductors may be used, for example, to form oscillators, filters, and other circuits.
At relatively low frequencies, integrated circuit inductors may be formed from solid metal traces. The solid metal traces may be arranged in straight lines or in spiral inductor shapes. Although performance may be satisfactory in some situations, operation at high frequencies poses challenges due to the skin effect and proximity effect. These challenges may make it difficult or impossible to form an inductor from a solid metal trace that performs satisfactorily. Challenges are also posed by the ongoing need to shrink device geometries. As semiconductor processing technologies progress, the maximum line widths permitted by semiconductor fabrication design rules tend to decrease, which tends to increase the minimum resistance of the metal lines on a device. This can adversely affect integrated circuit inductor performance.